Electric control for warning signals



March 24, 1942. J. A. ROOK ET'AL 2,277,457

ELECTRIC CONTROL FO R WARNING SIGNALS Filed Jan. 4, 1939 Y Patented Mar. 24, 1942 ELECTRIC CONTROL FOR WARNING SIGNALS James A. Book and Clay H. Rook, Los Angeles, Calif.

Application January 4, 1939, Serial No. 249,327

8 Claims.

This invention relates to electric controls for warning signals and the object of the invention is to provide a make and break contact switch having prolonged life.

Another object of the invention is to provide means for preventing pitting of the contact elements of a make and break switch.

Another object of the invention is to provide a wiping contact make and break switch for an electric control of the type shown in our Patent No, 2,145,634, dated January 31, 1939.

We accomplish the above and other objects of the invention, which will be apparent as the description proceeds, by means of the construction shown in the accompanying drawing, in which Fig. 1 is a top plan of the device constituting our invention, certain interior parts being shown in dotted lines;

Fig. 2 is a side elevation of the device shown in Fig. 1, the interior construction being shown in dotted lines;

Fig. 3 is a section on the line 3-3 of Fig. 1, looking in the direction of the arrows;

Fig, 4 is a top plan of the device with the operating lever arm removed;

Fig. 5 is a section on the line 55 of Fig. 1 looking in the direction of the arrows;

Fig. 6 is a bottom plan of the device with the base removed;

Fig. 7 is a perspective of the operating lever shaft and contact arm in disassembled relation; and

Fig. 8 is a perspective of the upper portion of the casing in which the shaft is mounted.

On the drawing, in which like reference characters indicate like parts on all the views thereof, l indicates the casing, which is preferably made of Bakelite or similar insulating material, having a base 2 provided with screws 3 by means of which it may be mounted on a suitable place onan automobile or other apparatus with which it is to be used.

Mounted for rotation within the casing l is a shaft 4 of conducting material to which is secured an operating lever arm 5 operatively connected to the throttle of the automobile. The lever arm 5 may be made of insulating material or of metal and suitably insulated from the conducting shaft 4. Carried by the shaft 4 is a metal contact arm 6.

The shaft 4 is mounted for rotation in the hollow post I of the casing, the post being provided with a cam face 8 on the upper peripheral edge thereof on which rides the projection 9 extending from the lever arm 5. It is apparent that this projection might be on the periphery of the shaft since its function is to ride upon the cam face 8 and thus reciprocate the shaft longitudinally as it is rotated by the lever arm 5.

Within the casing is a block of insulating material I0 having a contact ring ll of metal or other conducting material embedded in the upper face thereof which cooperates with a ring 12 having similar conducting properties which is secured to the inner face of the casing cover, the latter ring being electrically connected to the terminal I3 for a lead wire. The block H) has a recess l4 in the periphery thereof to one wall of which the bent end 15 of the conductive ring II is secured to provide a contact face, the opposing wall of the recess being non-conductive.

When the parts are assembled, the shaft is positioned in the hollow post I with the contact 6 located in the recess I4 and the parts held in assembled relation by means of the screw Hi, the spiral spring ll maintaining the conductive ring II on the block In in facial engagement with the conductive ring 12 on the inner face of the casing cover.-

As is apparent, the device is similar in construction and operation to the device covered by our Patent No. 2,145,634 above referred to, the objects of this invention being to prolong the life of the apparatus by preventing pitting of the cooperating contact parts.

As is well known, constant use of a make and break switch causes pitting and corroding of the contact elements, finally rendering them useless. We have remedied this defect by providing a construction in which the contact parts have a wiping or rubbing contact which keeps the contact faces clean and free from corrosion. When the shaft is rotated, the projection 9 rides on the cam face 8, thereby reciprocating the shaft longitudinally and carrying the contact 6 against the contact face I5 and across the same to provide a, wiping action. The upper peripheral edge of the casing is also provided with a cam face IS on which the operating lever arm 5 rides, the ends of the cam face forming stops to limit the movement of the lever arm.

A coil spring 19, which partially surrounds the shaft 4 is secured at one end to the lug 2D in the casing and at the other end to the lug 2| on the operating lever arm 5. This spring prevents play between the parts with consequent chattering since it pulls the shaft down during rotation.

A spring arm 22 which bears against the .upper end of the shaft 4 extends from the terminal 23 thus providing a wiping contact with the shaft which will keep these parts clean and free from pitting.

When the device is used on an automobile to indicate deceleration of the engine, the lever arm is connected to the accelerator of the engine so that when the accelerator is operated, the shaft will be rotated in clockwise direction and the contact 6 moved away from the conducting face 15. When, however, the engine is decelerated, the shaft will be rotated in anti-clockwise direction, carrying the contact 6 against the face l5 and reciprocated thereagainst to complete the circuit.

to the signal. The wiping of the contact 6 against the face I5 and the end of the spring arm 22 against the upper end of the shaft produces the wiping action covered by this invention.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is:

1. An electric control for warning signals comprisinga casing, a shaft mounted for rotary and reciprocating movement therein, a conductive friction element fixed with relation to said shaft, a second friction element loosely mounted on said shaft and in frictional engagement with said first named, friction element, a contact on said second friction element in conductive. relation with said first named friction element, a second contact secured to said shaft and movable therewith and positioned to engage the contact on said second named friction element and means causing said second contact to wipe across said first contact when the shaft is operating, and means whereby the shaft may be rotated and reciprocated.

2. An electric control for warning signals comprising a casing, a shaft, means mounting said shaft in the casing for rotary and reciprocating movement, a contact secured to said shaft, a loosely mounted conductive element on said shaft having a, portion positioned to be engaged slidably by said shaft carried contact in one direction of rotation of the shaft and means for rotating and reciprocating said shaft.

3. The device as described in claim 2 wherein there is a coiled spring associated with the shaft and the, casing. and partially surrounding the contact element comprising a stationary member and a relatively rotatable member, said elements having conducting portions in frictional engagement with each other, one of said members having a non-conductive portion, a movable contact, and means for moving said movable contact against the conductive face of the rotatable element said last named means including means for wiping it across the same when in contact therewith.

5. An electric control for warning signals comprising a rotatable conductive shaft and mounting means therefor, said shaft and mounting having a cooperating cam face and portion engaging the cam face for reciprocating the shaft as it is rotated, a contact carried by said shaft, a contact constructed and arranged for engagement by said shaft carried contact and remain in engagement therewith while the latter contact reciprocates longitudinally thercover, a spring contact carried by said mounting bearing against said shaft, and means for rotating said shaft.

6. The construction as described in claim 5 in which there is conductive element loosely mounted on the shaft to which the second named contact is. secured.

7. An electric control for warning signals comprising a rotatable shaft and mounting means therefor, a cam surface on said mounting means, cooperating means operatively connected to said shaft riding on said cam face for reciprocating the shaft during rotation thereof, a contact carried by said shaft for rotation and reciprocation therewith, a. conductive element loosely mounted on said shaft having a contact face constructed and arranged for engagement by said contact on the shaft in one direction of rotation of the shaft and remain in engagement therewith while the shaft carried contact reciprocates thereover.

8. An electric control for warning signals comprising a casing, a shaft of conductive material mounted for rotation and reciprocation therein, a contact secured to said shaft, a conductive element positioned to be engaged by said contact in one direction of rotation of the shaft, a spring pressed contact arm bearing against said shaft during every position thereof, and means for r0- tating and reciprocating said shaft.

JAMES A. BOOK. CLAY H. ROOK. 

